Schizophrenia

Abstract

Schizophrenia is a psychotic disorder characterized by distorted perception, dysfunctional beliefs that are false and often bizarre, abnormal affect that is either reduced in intensity or not in keeping with reality, and abnormal behaviour that can be disorganized, bizarre or catatonic. In most patients, it has a chronic course with numerous acute episodes and variable inter-episode remission. Multiple genetic and non-genetic factors are involved in the aetiology. Genetic predisposition remains the most important; several genes of small effect seem to be involved and some of these (neuroregulin, dysbindin, COMT) have now been reliably described. Illicit drug abuse is another risk factor, with important public health implications because of the widespread availability and increased acceptability of drug use. The mainstay of treatment is pharmacotherapy with antipsycchotic agents. Psychological treatments, particularly cognitive behavioural therapy may also be helpful. The first generation of antipsychotics (e.g. haloperidol, chlorpromazine), often termed ‘typical’, was characterized by potent blockade of the dopamine D2 receptor. The second-generation antipsychotics (‘atypicals’) have a more varied receptor profile typified by lower affinity for D2 receptors. The most troublesome side-effects of antipsychotics are extrapyramidal, endocrine, metabolic and sexual problems. Atypical antipsychotics have fewer extrapyramidal side-effects, but carry an increased risk of dysregulation of glucose and lipid metabolism and weight gain.